Clinical Features of Precocious, Synchronous, and Metachronous Brain Metastases and the Role of Tumor Resection.

OBJECTIVE: The purpose of this study was to clarify clinical features, outcomes, and the role of tumor resection in precocious, synchronous, and metachronous brain metastases. METHODS: Brain metastases were found before primary cancer detection in the precocious group, within 2 months after primary cancer detection in the synchronous group, and 2 months or later after primary cancer detection in the metachronous group. RESULTS: Of 471 patients with brain metastases, 93 (20%) were included in the precocious group, 76 (16%) in the synchronous group, and 302 (64%) in the metachronous group. The precocious group tended to be symptomatic, show a low Karnofsky Performance Status, and have a large single tumor, infrequent extracranial metastases, and frequent tumor resection compared with the other 2 groups. There were no differences in overall survival from the detection of brain metastases among the 3 groups in univariate and multivariate analyses. Of 471 cases, 97 (21%) underwent surgeries. Among this surgical cohort, overall survival from surgery was significantly shorter in the precocious group than in the metachronous group (P = 0.039). After adjustment for age, sex, tumor size, primary cancer, and the Graded Prognostic Assessment score, the hazard ratio for metachronous metastases was 0.52 (confidence interval, 0.29-0.95; P = 0.035). CONCLUSIONS: The timing of brain metastasis diagnosis is not a modifiable factor but affects patient demographics and treatment strategies. In particular, the precocious group is a unique subset of brain metastases that require special consideration during clinical decision making.

Hazard of ultraviolet radiation emitted in gas metal arc welding of mild steel.

OBJECTIVES: Ultraviolet radiation (UVR) emitted during arc welding frequently causes keratoconjunctivitis and erythema in the workplace. The degree of hazard from UVR exposure depends on the welding method and conditions. Therefore, it is important to identify the UVR levels present under various conditions. METHODS: We experimentally evaluated the UVR levels emitted in gas metal arc welding (GMAW) of mild steel. We used both a pulsed welding current and a non-pulsed welding current. The shielding gases were 80% Ar + 20% CO2 and 100% CO2. The effective irradiance defined in the American Conference of Governmental Industrial Hygienists guidelines was used to quantify the UVR hazard. RESULTS: The effective irradiance measured in this study was in the range of 0.51-12.9 mW/cm2 at a distance of 500 mm from the arc. The maximum allowable exposure times at these levels are only 0.23-5.9 s/day. CONCLUSIONS: The following conclusions were made regarding the degree of hazard from UVR exposure during the GMAW of mild steel: (1) It is more hazardous at higher welding currents than at lower welding currents. (2) At higher welding currents, it is more hazardous when 80% Ar + 20% CO2 is used as a shielding gas than when 100% CO2 is used. (3) It is more hazardous for pulsed welding currents than for non-pulsed welding currents. (4) It appears to be very hazardous when metal transfer is the spray type. This study demonstrates that unprotected exposure to UVR emitted by the GMAW of mild steel is quite hazardous.

Hazard of ultraviolet radiation emitted in gas tungsten arc welding of aluminum alloys.

Ultraviolet radiation (UVR) emitted during arc welding frequently causes keratoconjunctivitis and erythema. The extent of the hazard of UVR varies depending on the welding method and conditions. Therefore, it is important to identify the levels of UVR that are present under various conditions. In this study, we experimentally evaluated the hazard of UVR emitted in gas tungsten arc welding (GTAW) of aluminum alloys. The degree of hazard of UVR is measured by the effective irradiance defined in the American Conference of Governmental Industrial Hygienists guidelines. The effective irradiances measured in this study are in the range 0.10-0.91 mW/cm(2) at a distance of 500 mm from the welding arc. The maximum allowable exposure times corresponding to these levels are only 3.3-33 s/day. This demonstrates that unprotected exposure to UVR emitted by GTAW of aluminum alloys is quite hazardous in practice. In addition, we found the following properties of the hazard of UVR. (1) It is more hazardous at higher welding currents than at lower welding currents. (2) It is more hazardous when magnesium is included in the welding materials than when it is not. (3) The hazard depends on the direction of emission from the arc.

Diffuse large B cell lymphoma of the cranial vault: two case reports.

Malignant lymphoma of the cranial vault is a rare entity and the tumor growth patterns are not well understood. Here we report two cases of malignant lymphoma involving the scalp and epidural space with slight changes in the intervening skull. A 63-year-old woman presented with a scalp mass in her right frontal area. Computed tomography (CT) and magnetic resonance (MR) imaging demonstrated mass lesions in the scalp and epidural space with slight osteolytic changes in the intervening skull. She underwent resection of the lesions. A 53-year-old man presented with a mass in his right frontal area. CT and MR imaging showed mass lesions in the scalp and epidural space without changes in the skull. He underwent resection of the lesions. The histopathological diagnosis was diffuse large B cell lymphoma in both cases. Microscopic examination of the intervening skull found that the bone marrow was diffusely replaced by lymphoma cells, and lymphoma cells extended to the extra- or intra-cranial space along the emissary veins without destruction of the cortical or trabecular bone. These histopathological findings explain the radiological findings and provide the clues to elucidate the mechanism of extension of cranial vault lymphoma.

Prediction of neurological recovery using apparent diffusion coefficient in cases of incomplete spinal cord injury.

BACKGROUND: Magnetic resonance imaging is useful in evaluating acute spinal cord injury. Apparent diffusion coefficient (ADC) values obtained by diffusion-weighted imaging can differentiate cytotoxic edema from vasogenic edema through microscopic motion of water protons. OBJECTIVE: To determine whether ADC values in the cervical spinal cord match neurological grades and thus predict functional recovery in patients suffering from cervical spinal cord injury. METHODS: Diffusion-weighted images were obtained using 15 axial slices covering the cervical spinal cord from 16 consecutive patients. ADC values were determined for both gray and white matter. All patients were treated surgically. Patient neurological status was evaluated preoperatively and postoperatively with the Frankel classification and neurosurgical cervical spine scale. One patient had complete spinal cord injury and showed no recovery. Using 15 patients with incomplete injury, we analyzed correlations between preoperative ADC values and neurological grading, degree of postoperative recovery, or cavity formation in follow-up magnetic resonance images. For comparison, ADC values of 11 healthy volunteers were also calculated. RESULTS: There was significant correlation between ADC values and degree of postoperative recovery (P = .02). ADC values of patients showing cavity formation were significantly lower than those of patients without cavity formation (0.70 vs 0.96 × 10⁻³ mm²/s; P = .01). The cutoff ADC value of 0.80 × 10⁻³ mm²/s resulted in 75% sensitivity and 81.8% specificity for predicting cavity formation. CONCLUSION: Low ADC values in acute spinal cord injury may indicate postoperative cavity formation in the injured spinal cord and predict poor functional recovery.

Subependymoma in the lateral ventricle manifesting as intraventricular hemorrhage.

A 32-year-old man presented with subependymoma in the lateral ventricle causing intraventricular hemorrhage and manifesting as severe headache and disturbance of consciousness. Computed tomography on admission showed a massive intraventricular hemorrhage and acute obstructive hydrocephalus. Cerebral angiography revealed no abnormal findings. Emergency external ventricular drainage was performed, and his neurological deficits gradually improved. Magnetic resonance imaging at 5 weeks after admission showed a tumor arising from the septum pellucidum or the floor of the right lateral ventricle, appearing as a mixed-intensity solid tumor, which was partially enhanced following gadolinium administration. The tumor had arisen from the septum pellucidum and was totally removed via an interhemispheric anterior transcallosal approach. Histological examination found typical subependymoma, with little vascularity. Intraventricular hemorrhage from cerebral neoplasms is usually due to highly vascular tumors. Since subependymomas are quite benign and show poor vascularity, intraventricular or subarachnoid hemorrhages are very rare, but do occasionally occur.

[Case of enlargement of an intradiploic epidermoid cyst by a head contusion].

We report a case of enlargement of a intradiploic epidermoid cyst following head trauma in a 19-year-old man. The patient had a swelling on the right side of his forehead from the time of his birth. He sustained a bruise in this region when he was 15 years old, following which the swelling gradually enlarged. When the diameter of the mass increased to 5 cm, he visited our hospital. Computed tomography (CT) scan of the head showed a subcutaneous mass of low density extending from the diploe to the outer tables of the skull. Magnetic resonance imaging (MRI) showed a hyperintense mass in both T1- and T2-weighted images. During the operation, we found a tumor that was intradiploic and had a thin capsule. The effusion from the tumor resembled an old hematoma, and the tumor did not involve the paranasal sinuses. We concluded the operation by performing cranioplasty using artificial bone. Histological examination revealed that the thin capsule consisted of stratified squamous epithelium and ciliated epithelium. Needle-like cholesterol crystals and hemosiderosis were seen shown in the granulation-like tissue. On the basis of these findings, we diagnosed the mass to bean intradiploic epidermoid cyst and thought that it might have grown following head trauma associated with chronic hemorrhage. This paper reviews the differential diagnosis and pathologic findings of the intradiploic epidermoid cyst along with some previously published cases.

Subarachnoid hemorrhage caused by rupture of a distal anterior inferior cerebellar artery aneurysm--three case reports.

Three female patients, two under 35 years old, presented with ruptured aneurysms of the distal anterior inferior cerebellar artery (AICA) manifesting as subarachnoid hemorrhage. The first patient had a ruptured saccular aneurysm of the meatal loop of AICA, which was treated by direct neck clipping. The second patient had a ruptured aneurysmal lesion that arose from a microvascular anomaly of the dorsolateral portion of the AICA, which was successfully treated by trapping. The third patient was dead on arrival, and autopsy revealed a ruptured saccular aneurysm in the meatal loop of the AICA. The mechanism of development of distal AICA aneurysm remains unclear, and some cases indicate a complicated causal relationship between the aneurysms and vascular anomalies. Neurosurgeons need to carefully evaluate the vascular structure around the aneurysms by preoperative angiography in each case, and select the most appropriate strategy.

[Case report of lumbar discal cyst].

The authors describe a rare case of lumbar discal cyst which produced manifestations similar o lumbar disc herniation. A 33-year-old man, who had had a crick in the back 3 months previously, suffered from severe low back and right lower-extremity pain. The neurological examination showed the L5 radiculopathy through the positive straight leg-raising test, no motor weakness nor sensory disturbance with normal reflexes. Magnetic resonance imaging demonstrated an oval shaped extradural lesion with a low signal intensity on T1-weighted images and a high signal intensity on T2-weighted images. Additionally, the surrounding rim of the cyst was enhanced with the addition of Gd-DTPA. As we diagnosed a lumbar discal cyst with severe symptoms, the patient received emergent surgery. The symptom disappeared immediately after surgery. This case implies that early surgery for discal cyst may be an effective means to obtain release from symptoms.

[Nontraumatic arterial dissection of the anterior cerebral artery: six cases report].

Nontraumatic arterial dissection of the anterior cerebral artery (NAD-ACA) is a relatively rare disease entity, although case reports have recently been increased. We treated 6 patients suffering from NAD-ACA from January 1996 to December 2003, and the neuroradiological findings together with the clinical courses were reviewed. There were 3 males and 3 females with a mean age of 57.7-year-old, ranging from 41 to 65. Five patients had a past history of hypertension and one diabetes mellitus. At the onset, all patients presented with clinical manifestations of cerebral ischemia. Among them, all exhibited contralateral hemiparesis with greater weakness of the lower extremity, and two patients exhibited headache. Initial angiography revealed the pearl and string sign in four patients and string sign, tapered occlusion in each one. Follow-up angiographies revealed sequential changes in all patients; four improved and two progressed. Main anatomic site of the lesion was as follows; five in the A2 and one in the A1 portion, in addition, one patient was complicated by saccular aneurysm, one by PCA dissection, and two had with saccular aneurysm contralateral ACA & MCA and VA dissection each other. Four patients were treated conservatively by intravenous administration of argatroban, one by intravenous administration of Dextrane and one by anti-platelet agent in the acute stage. All patients were treated by anti-platelet agents in the chronic stage. Good recovery was achieved in five patients, but one who suffered from severe subarachnoid hemorrhage in the chronic stage died. Our experience suggests that hypertension and/or the succeeding abnormal structural changes in the arterial wall may contribute to the occurrence of this disease. NAD-ACA showing clinical manifestations of cerebral ischemia could result in a relatively good prognosis; however, attention should be paid to patients treated conservatively with a very closed follow-up angiography to prevent a possibility of severe hemorrhage.

[Hemangioblastoma of the optic nerve growing like a dumbbell through the optic canal: case report].

We report a case of optic nerve hemangioblastoma in a 29-year-old man without a family history of von Hippel-Lindau disease or the other organ symptoms. He had progressive loss of vision and proptosis with a dull pain in his right eye. Magnetic resonance image (MRI) showed a gadolinium (Gd) enhancing solid tumor involving the prechiasmal right optic nerve with intraorbital extension. The tumor contained many signal voids of vessels and grew like a dumbbell through the right optic canal. Digital subtraction angiography demonstrated that the hypervascular tumor was fed by the ophthalmic artery and the orbital ramus of the middle meningeal artery. We succeeded in total resection of this hypervascular tumor by orbito-zygomatic approach. This tumor grew unusually like a dumbbell because it occurred in the optic nerve at the part of the optic canal. Histological examination revealed the tumor to be a characteristic hemangioblastoma. The postoperative course was uneventful. Supratentorial hemangioblastomas, especially optic nerve hemangioblastoma are extremely rare. This paper reviews the previous published cases and discusses their findings.

[A case of peripheral-type primitive neuroectodermal tumor arising in the dura mater at the frontal base].

A 7-year-old boy was admitted to our hospital because of headache and frequent vomiting. The patient was noted to have papilloedema and mild palsy of the right abducent nerve. Magnetic resonance image (MRI) revealed a large tumor in the frontal base with tumoral hemorrhage. Angiography showed the tumor was fed by anterior meningeal arteries. At surgery, the tumor was arising in the dura mater at the frontal base, and was removed totally. Histological examination showed the tumor to be composed of small cells with uniform round nuclei and minimal cytoplasm. Immunohistochemical studies were positive for MIC-2, NSE, C-KIT, vimentin, Class III-beta tublin and glycogen, but negative for NFP, synaptophysin, chromogranin A and GFAP. MIB-1 labeling index was 40-50%. The tumor was histologically confirmed to be peripheral-type primitive neuroectodermal tumor(pPNET). Following surgery, he underwent whole brain, whole spine and local radiation therapy(30 Gy in total respectively) and received two 5-day cycles of chemotherapy, consisting of intravenous administration of cisplatin 20 mg/m2/day, etoposide 60 mg/m2/day and IFOS 900 mg/m2/day. After these therapies, follow-up radiological examination showed there was no recurrence of the tumor for 24 months. Intracranial pPNET is rare. Ewing sarcoma and pPNET(ES/pPNET) is the designation given to a family of small round cell tumor arising in bone or soft tissues. Intracranial PNETs are devided into central nervous system PNET(cPNET) and pPNET. It is necessary that intracranial PNETs are divided into two types of PNETs because of different prognosis between these tumors. MIC-2 is a specific marker for pPNET/ES family and is useful in the differential diagnosis of these two types of tumors.

A case of angioglioma composed of astrocytoma with a papillary growth pattern: immunohistochemical and ultrastructural studies.

We report a case of a large cystic astrocytoma associated with arteriovenous malformation in the right cerebral hemisphere of a 16-year-old boy. Neuroimaging showed large abnormal vessels with flow voids and arteriovenous shunt around the cystic lesion. Histologically, the cyst wall was formed by abnormal vasculature and clusters of glial cells forming a papillary growth pattern. The abnormal vasculature consisted of dilated vein-like vessels and medium-sized arteries with incomplete media, and was diagnosed as an arteriovenous malformation. Immunohistochemically, glial fibrillary acidic protein (GFAP) decorated both the perikaryon and the processes of the glial tumor cells. They were negative for epithelial membrane antigen (EMA), cytokeratin, and S-100 protein. Ultrastructurally, the tumor cells were rich in intermediate filaments, and neither cilia, microvilli, nor ependymal rosettes were verified. Based on these morphological features and the low MIB-1 labeling index of 0.8%, the glial tumor was diagnosed as astrocytoma, Grade II, according to the World Health Organization (WHO) tumor classification. An association of glioma with various types of vascular anomalies has been designated as angioglioma. A unique feature of the present case, however, is a papillary growth pattern, which is not listed in the current WHO classification of brain tumors. The recognition of the occurrence of such cases would be important in differential diagnosis of papillary ependymoma and choroid plexus papilloma.